Electromagnetic mechanism



Feb. 13, 1940. E. BlLGART 2,189,934

ELECTROMAGNETI C MEGHANI SM Filed April 7, 1939 I72 2/@ 72 for $502736; Cm

fir/e JJ I I: 4/3? 2/6/4 44 15 ozyzgys Patented Feb. 13, 1940 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to an electromagnetic mechanism in the natur of a signaling device, in that it includes means for causing a sound or audible signal and means for simultaneously producing a mechanical movement. One object of the invention is to provide a mechanism in which a single electromagnetic coil serves for actuating both the audible signal and the movable mechanism. Another object is to provide a mechanism of simple and sturdy construction adapted for economical manufacture. The invention consists in certain features and elements of construction in combination, as herein shown and described and as indicated by the claims.

In the drawing:

Fig. 1 is a front elevation of an electromagnetic mechanism embodying this invention.

Fig. 2 is a sideelevation of the same as viewed from the right.

. Fig. 3 is a side elevation of the device as viewed from the left.

The mechanism shown in the drawing isapplicable to a wide range of uses, including amusement devices, signaling apparatus and display advertising mechanisms involving the use of sound and motion. It may be understood that the invention is susceptible of embodiment in a variety of forms, and that the structure shown herein is merely illustrative. It includes a base I and an upright supporting plate 2 to which there is secured by a strap 3 an electromagnetic coil 4 designed to operate as a solenoid and having a movable core 5 mounted for reciprocation axially within the coil. A conductor wire 4 extends from one end of the coil to a binding post 6 from which a lead wire I may be understood as connecting with a suitable source of electrical energy, such as the battery indicated diagrammatically at 8.

From the other end of the coil i a wire 9 is connected to the fixed contact terminal ID of a sound-producing device in the nature of an electric buzzer. The buzzer includes an armature l l extending opposite the lower end of the coil 4 and spaced therefrom in position to vibrate toward and from the coil when the latter is energized. The armature is supported by a spring member l2 secured to a bracket l3 projecting from the supporting back plate 2 and in the form shown the spring member 12 includes an offset portion l4 spaced from the armature and standing normally in contact with the terminal 59. Said terminal it is carried by a metallic angle member 15 secured to a mount it of insulating material, which is fastened to the back plate 2; but

member 29 supported by the back plate 2 (or. 177-324) g I the bracket i3 is in direct contact with the back 7 plate 2 and thus serves to ground the circuit of the coil and buzzer mechanism. A ground wire I! may be attached to the binding post it, if

required, to insure a good connection with the part to which one side of the battery is grounded, as indicated at I8.

The metallic core 5 of the solenoid is pivotally connected to a lever 29 fulcrumed at it on a bracket 22 supported by the back plate 2 and, as 1 shown, the leverextends through a clearance opening 23 in the back plate so that its opposite end portion 24 is available for connection to any, movable element or mechanism, as by means of a link 25 of which a fragment is shown A relatively light spring 26 anchored to the upper portion of the plate 2 normally holds the core 5 at the upper limit of its range of movement with most of its mass withdrawn from the central space within the coil 4. However, upon closing the circuit, as by means of a switch 21 the lead wire I the coil is energized, and draws the core 5 downwardly to the lower limit at which it is stopped by encounter of the lever to with the lower edge 28 of the clearance opening 23. This brings the lower end of the core 5 closely adjacent the armature H of the buzzer mechanism so as to concentrate the magnetic sufiiciently to produce an effective actuation of the armature. The latter is drawn toward the magnetic core 5 but its slight movement in this direction breaks the electrical connection between the terminal I 0 and the spring arm l4 thus interrupting the circuit and allowing the armature ll to return to its initial position under stress of its spring-supporting member I2. This re-establishes the circuit through the contacts i l and I4 re-energizing the coil 4 and its magnetic core 5 and again drawing the armature ll toward the core. Thus the armature is caused to vibrate rapidly, producing a buzzing sound, which is considerably amplified by the provision of a metallic and formed with a slot or notch 30 through which the free end of the armature ll extends so that it hammers alternately against opposite sides of the slot as it vibrates.

The interruption of the circuit between the contacts In and I4 occurs repeatedly, but too rapidly to cause the coil 4 to rel-ease its plunger core 5 as long as the switch 2'! remains closed; hence, the plunger 5 will be held at or adjacent its lower limit, and the portion 24 of the lever 20 will be elevated while the circuit is thus maintained. Thus it will be evident that the mechanism may be employed for various purposes. For example, the arm 24 may operate a visual signal, while the buzzer will serve to sound an alarm, or call attention to the signal at one position of the latter. Or the mechanism may operate an advertising device having a visibly movable portion which is shifted from one limit to another at predetermined intervals, and whose movement is to be accompanied by a sound such as the buzzer can produce. Obviously, the slotted member 29 may be replaced by a gong, and a suitable hammer may be attached to the armature H to convert the buzzer into an electric hell, if de-,

sired; and, for continuous operation the switch indicated at 2! will be mechanically actuated by a continuously running mechanism such as a motor. But for whatever use it may be designed, the mechanism has the advantage of requiring only a single coil to actuate the sound producing mechanism and the movable element operated by the lever Zll, thus rendering the device economical to manufacture and permitting of a very simple and reliable operating circuit.

While there is shown and described herein certain specificstruoture embodying the invention, it will be manifest to those skilled in-the art that various modifications and re-arrangements of the parts may be made without departing from the spirit and scope of the invention, and that the same is not limited to the particular form herein shown and described, except in so far as indicated by the appended claims.

I claim:

1. The combination with a movable member and a sound producing device, of an electro-magnetic coil having a movable core operatively connected to the movable member and said sound producing device including an armature, said core being normally disposed at one end of the coil and being movable toward the other end when the coil is energized, a make and break device in circuit with the coil and having a portion connected to the movable armature for actuation thereby, the armature being disposed adjacent said other end of the coil and the approach of the core serving to concentrate the magnetic field sufilcientlyfor efifective actuation of the armature and its connected sound producing device.

2. The combination with the movable member and a sound producing device of an electromagnetic coil having a movable core operatively connected to the movable member-and said sound I producing device including an armature, means for positioning the movable core at one end of the coil and partly entered therein, said core being movable within said coil towards the opposite end thereof when the coil is energized, a

make and break device in circuit with the coil and having a portion connected to the movable armature for actuation thereby, said armature being positioned adjacent the opposite end of the coil, and means for arresting the core at a point in proximity to the armature but out of contact therewith vfor concentrating the magnetic influence of the coil upon the armature to cause operation thereof and the connected sound producing device.

3. The combination with a movable member and a sound producing device, of an electromagnetic coil having a movable core operatively connected to the movable member and said sound producing device including an armature, the magnetic circuit of the coil being designed to initially actuate the core and then the armature whereby to cause sequential actuation of the movable member and the sound producing device, when the coil is energized, a make and break device in circuit with the coil and having a por-- tion connected to the movable armature for actuation thereby, and stop means for arresting the core member in a position to concentrate the magnetic influence of the coil upon the movable armature, whereby to vibrate said armature. ERIC E. BILGART. 

